THE EFFECT OF PROPICONAZOLE ON FOLIAR FUNGAL DISEASES, HERBAGE YIELD AND QUALITY OF PERENNIAL RYEGRASS

The fungicide propiconazole, applied as a foliar spray to swards of pe rennial ryegrass (Lolium perenne) at four sites in England from 1990 t o 1992, reduced the incidence of powdery mildew (Blumeria graminis), D rechslera leaf spot (Drechslera spp.) and Rhynchosporium leaf blotch ( Rhynchosporium spp.), increased the number of leaves per tiller and re duced the proportion of dead leaves. Propiconazole increased yield, by 6-7%, at harvests in mid-May, but had no effect at harvests in late J une, when the cut herbage was dried to produce hay, although in one ha y crop, in vitro organic matter digestibility was increased from 575.6 to 588.5 g kg(-1) (P < 0.05). Further research is required to determi ne the rationale and optimum timing of fungicide application to grassl and.